LSF / LSOH Twin & Earth

[Click-Sure]

I've taken the decision to move over to using LSF twin and earth for all my new installs and rewires on the grounds that it is safer and, in my eyes helps to future proof the installation given that PVC/PVC twin and earth (i feel) is likely to be phased out soon. Even if it is a pain to work with, and more expensive (where liason with customer is important) and my local wholesalers dont hold much of it in stock.

That idea goes on with using the loop-in-switch method for lighting circuits so that changing luminaires is a doddle for the end-user and not installing ring circuits (the death of which is inevitable, my thoughts on such have allready been made clear).

I like to think I'm doing right for my customers by doing this, and I always explain my chosen way of working fully, and generally t is respected.

Your thoughts please.

 

[Spark123]

Why not - as long as the customer is happy with the additional expense for the extra safety (fumes given off in a fire etc) then I don't see the problem.

 

[ban-all-sheds]

Hmmm.

LS0H cable is traditionally specced for enclosed environments where people can't get away from a fire. In a house, unless you expect your wiring to be the cause of a fire, I wouldn't have thought it would matter. If the fire started elsewhere then if anyone was still inside by the time it had set the cables alight and the fumes had become a problem wouldn't they be doomed anyway? Or already dead?

 

[NotHimAgain]

With regard to LSF / LS0H cable in domestic installations, I agree with BAS.

Note that there is a big difference between LSF and LS0H. Also note, that for its use to be effective all of the containment should also have the same fire performance. This also applies to all other building materials.

However, you may find that 'standard' PVC is phased out by the manufacturers in due course.

Loop in wiring (2 plate) is fine provided all joints are accessible for maintenance. There is no reason why this can't be achieved on most installations. This will also help to facilitate the 'building control systems' that are beginning to find their way into the domestic market.


Rings verses radials has been discussed many times (before someone links to the IET discussion - I know Roger Lovegrove and he has told me that he actually has no problem with rings mains ).

However, please bear in mind that if you are basing your radial circuits on 'ring main technology' - specifically BS 1363 socket outlets - that these will follow the ring main out of the door. You will then have to follow the same practices of some of our EU partners and restrict the number of outlets per run. This will result in more cables, larger distribution boards and more holes in joists to achieve the same level of service.

Group Schneider 'have it in' for the ring main as their recent 'white paper' shows www.emconline.co.uk/story.asp?sectioncode=225&storyCode=3147240. IMO, the arguments used are poor, unproven and clearly designed to support their commercial purposes. They, along with most other major players, have 'structured wiring' systems in the wings, and the ring main does not fit in with them.

Note that these systems are 'Plug and Play' and when added to the modular building elements - in common use on large projects - spell the end of the line for many 'electricians'. These modules (plant rooms, hospital ward rooms, wash rooms etc.) will no doubt eventually be constructed in the latest 'cheap labour' area and be shipped to the UK in container format - soon we will do little more that plug them in.

Keeping the ring main is akin to following the philosophy of King Canute - but it might delay things a bit .

 

[holmslaw]

..

 

[NotHimAgain]

He put the argument against ring mains in the IET debate.

As such he is relevant in my post - do you have some problem with that.

 

[ban-all-sheds]

Group Schneider 'have it in' for the ring main as their recent 'white paper' shows www.emconline.co.uk/story.asp?sectioncode=225&storyCode=3147240. IMO, the arguments used are poor, unproven and clearly designed to support their commercial purposes. They, along with most other major players, have 'structured wiring' systems in the wings, and the ring main does not fit in with them.

Since nothing that they want to sell is hampered by the option of ring finals being an available design, I don't see why they need to worry. If their pre-fabricated plug'n'play systems are attractive to builders because of their price they aren't going to refuse to buy them just because they end up with radials instead of rings in their buildings, are they?

 

[NotHimAgain]

I must admit I don't understand why they have bothered to include 'rings mains' in their white paper. I cannot see that the continued use of ring final circuits would have any real effect on their wiring products.

However, the BS 1363 socket outlet is another matter, and this may be behind their actions.

There was a project in the EU to develop a standard plug and socket. It got to the stage of a prototype (made by MK) but ultimately failed to gain acceptance. This went on for over 25 years.

Now I can see that Group Schneider and others would be happy to see a standardized socket outlet. The committees that consider these things are staffed by 'volunteers', and this often means by those that can give their time for free. Group Schneider often book all of the 'down town' hotel space at CENELEC and IEC meetings .

 

[ban-all-sheds]

That's just the way that every industry has always operated, and I'm sure you could point to the death of all manner of crafts over time as new materials and new techniques have evolved.

It's good that you are thinking about King ****. (Although most people have it completely AAF about the action for which he is famous )

 

[holmslaw]

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[ban-all-sheds]

He's not the nutcase who thinks that if you replace a fuse in an FCU you become responsible for everything back to the power station turbines, is he?

 

[ericmark]

I can see the 13A socket being modified to take heavier cables but in order to use the 13A socket with a radial circuit able to feed for example a kitchen it will need to be feed with 6mm cable and many sockets will not take two 6mm cables.

The German Schuko sockets are not allowed in the UK as reversible and that means the only existing socket which is not already on decline would be the Australian one. And even that has no fuse so would require the return to using 2A, 5A, and 15A versions if not fused so only way to replace the 13A socket would be to design a new fused plug from scratch. This would be unlikely to catch on so more likely the 13A socket will remain.

As to cable change I realise the Ali-tube cable is what the manufactures have designed as the replacement for twin and earth and I can see the advantages in using it. On large jobs a tray of Ali-tube looks far better than twin and earth and a lot easier to form into place. Looks similar to mineral insulated which always did look good.

But the 17th does not seem to follow as there is only a table for twin and earth current carrying capacity in normal home. And in spite of the advantages of not needing RCD protection it is still not offered for sale in DIY sheds. However neither is LSF twin and earth and if you are going to move over to 90degC rated cable why only go half way may as well go whole hog!

 

[holmslaw]

..

 

[NotHimAgain]

He put the argument against ring mains in the IET debate.

As such he is relevant in my post - do you have some problem with that.

Usually when people name drop its to demonstrate their higher status, so I just wondered who he was as I've never heard of him.

Well mentioning Roger is hardly likely to increase my status . He is now in his seventies, and whilst he is still active in the Wiring regulations committees and similar, I would hardly consider him to be 'a claim to fame'. I know lots of others that I could mention if I thought that somehow their status would enhance mine.

However, to those that have read the IET debate - I am simply pointing out that Roger took a position because he was asked to - he could have made the argument for the opposing view - such is the nature of that debate.

Finally it comes down to preference - there is no overwhelming technical argument for either solution.

 

[NotHimAgain]

The BS 1363 socket outlet was one of the stumbling blocks to the 'Euro plug'. Another was the use of shutters as the French didn't like them

A solution was proposed for the BS 1363 involving placing a fuse in the socket rather than in the plug. The French now apparently like shutters so that's alright then .

IMO, all of this revolves around the protection of flexes and the view that you take on it. It appears that many EU Standards apply a 16A limit on outlets for general use - I am sure it is detailed somewhere but I am not going to search all of the Standards to find it . This seems to inform the limits set on the number of outlets per radial circuit.

As far as I know the UK has a relatively high number of outlets per room and accommodating this with radials using unfused plugs could lead to a high number of circuit runs. I say could, because if we re-engineer the whole problem, we could mitigate this.

Now who will design a new system for us - any volunteers - forget traditional arrangements, lighting and power, circuits sourced from the intake, etc. Think of trees and multiple distribution points, and don't forget to include communications and entertainment systems too .